Posttraumatic Stress Disorder (PTSD) has been linked to poor health outcomes and increased medical service utilization, and the data suggest that treatment may lead to improvements in health and reductions in utilization. The majority of available data is from specialty populations, such as veterans, violent crime victims, pain patients, or heart transplant recipients. To date, few studies have examined the relationships between PTSD, health, and utilization in a civilian primary care population. This information is of critical importance because most patients with PTSD seek treatment in medical rather than mental health settings. In our pilot study in a civilian primary care setting we found that, compared to patients without PTSD, the 9% of the patients with self-reported PTSD evidenced more physical symptoms, worse general health functioning, and greater medical service utilization. Despite prevalence and association with poor health and high utilization, PTSD appears to remain generally unrecognized in primary care settings. Most patients with PTSD in the general population are unaware that they have the disorder or that it may have some relationship to their health problems. It is largely unknown to what extent primary care providers (PCPs) identify PTSD and initiate intervention. It is also unclear whether patients follow through with referrals after being apprised of the diagnosis, or whether obstacles impede their access to treatment. To address these issues, primary care patients will participate in diagnostic interviews to determine PTSD status and psychiatric co-morbidity and complete self-report questionnaires about their physical health. Medical records will be reviewed to assess medical conditions and utilization rates as well as PCP's PTSD diagnosis and treatment referral. Such descriptive data is necessary to develop a research program aimed ultimately at understanding the relationships between PTSD, medical utilization, and health so that effective PTSD detection and/or treatment interventions can be designed for primary care settings.